Citing inside sources, an Automotive News report maintains that FCA senior executives discovered thousands of vehicle sales were unaccounted for during a mid-2015 internal inquiry.

The insiders claim that the practice of reporting sales without legitimate buyers was put to an end by Head of U.S. Sales Reid Bigland following the review.

The FCA sources did not identify the time frame covered by the inquiry but indicated that between 5,000 and 6,000 vehicles had been booked as sold by dealers and then “unwound.”

The sales numbers were said to have been overstated as a result of pressure to keep FCA’s year-over-year monthly sales streak alive. Since it exited bankruptcy in 2009, FCA has maintained 75 consecutive months of sales increases.

The claims come to light as both the Securities and Exchange Commission and the Department of Justice have begun investigations into FCA sales practices.

FCA has refused to comment on the matter.

Update: Fiat Chrysler has indicated that it is in the process of changing its U.S. sales reports to make them more transparent. As a result of the changes, FCA says its sales streak ended in September 2013 at 40 months.